package leetcode;

/**
 * 给你一个由 '1'（陆地）和 '0'（水）组成的的二维网格，请你计算网格中岛屿的数量。

岛屿总是被水包围，并且每座岛屿只能由水平方向和/或竖直方向上相邻的陆地连接形成。

此外，你可以假设该网格的四条边均被水包围。

 

示例 1：

输入：grid = [
  ["1","1","1","1","0"],
  ["1","1","0","1","0"],
  ["1","1","0","0","0"],
  ["0","0","0","0","0"]
]
输出：1

示例 2：

输入：grid = [
  ["1","1","0","0","0"],
  ["1","1","0","0","0"],
  ["0","0","1","0","0"],
  ["0","0","0","1","1"]
]
输出：3

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/number-of-islands
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。
 * @author aicview
 *
 */

public class NumIsLands {
	
	public int numIslands(char[][] grid) {
        int c = 0;
        for(int i = 0;i<grid.length;i++){
            for(int j = 0;j<grid[i].length;j++){
                if(grid[i][j] == '1'){
                    deepSearch(grid,i,j);
                    c++;
                }
            }

        }
        return c;
    }

    public void deepSearch(char[][] grid,int i,int j){
        if(grid == null|| i<0||i>=grid.length
        ||j<0||j>=grid[i].length){
            return;
        }

        if(grid[i][j] != '1'){
            return;
        }
        grid[i][j] = '0';
        deepSearch(grid,i+1,j);
        deepSearch(grid,i-1,j);
        deepSearch(grid,i,j-1);
        deepSearch(grid,i,j+1);
    }

}
